i was wondering if there was an easy, or relatively easy way to convert a single speed, such as a bmx cruiser, to a multispeed. i am just looking to put a rear der on for a little extra comfort while commuting, that is all i will be using this bike for. can you just attach a der hanger to the back and go for it? or is it pretty much just a huge pain?

Some low-end Shimano dérailleurs have an integral "claw" adapter to essentially make their own hanger, and you can buy the adapter separately. But there's a lot more to that change than you might think.

• shifters
• cable and housing
• cable and housing support points on the frame
• how to mount the cassette/freewheel to the hub
• need to replace wheel hub? i.e. complete wheel rebuild or replace
• width of hub/cassette/freewheel compared to the frame dropout spacing
• resize chain
• learning to shift

A bike designed as a single-speed will be a PITA to convert. A bike designed as a multi-speed and converted to single-speed will already have some of the features you need.

yeah, i would have a wheel built for me at the shop, but i am kinda worried about frame size with the new hub i would use. what i really would like is something like a dmr or giant stp, but without all the super bad parts, and without the super bad price tag. some of the dmr bikes come as single speed, but they say they are easily convertible to like a nine or eight speed. i think they just have a bolt on der hanger, but i am not sure if they have holes drilled in the dropout to bolt it to. i dont have a lot of extra droput space, since cruisers are designed to be light and raceable, so i dont think i would have the room to drill a hole for it, and still keep the dropout structurally secure, but if i can bolt something on to the axle, i think it might be possible. what do you think? also, i would buy a new chain, the one it would have would be a single speed, and i know that wouldnt turn out to well for me.

You don't need holes. They clamp in the dropout. There is a head that the cassette needs to clear, though.

Would an internally geared hub work? It'd still require some work (plus an expensive new rear wheel) but I''ve seen some SS bikes retrofitted with a Nexus system. The Harris San Jos8 comes to mind:

https://www.sheldonbrown.com/harris/b...os8/index.html

i was initially thinking of an internal, but i wouldnt have a clue how to work on it, it seems like a real pain to install, and i would have to get some axle adapters, so i thought maybe a der would be easier. has anyone installed one of those or has any experience with them at all?